A novel all-in-one integrated flexible supercapacitor based on self-healing hydrogel electrolyte

Hydrogel electrolytes have special significance in the fabrication of flexible supercapacitors, which can withstand deformation and physical damage. Especially, there still exists a huge space in the design of self-healing integrated flexible supercapacitors with all-in-one structure that can reduce interfacial contact resistance, avoid the displacement and delamination deformations and prolong the lifetime. Herein, a self-healing integrated flexible supercapacitor has been prepared via in-situ polymerization of aniline on both sides of the physically cross-linked self-healing polyvinyl alcohol/phytic acid hydrogel electrolyte film. The self-healing integrated flexible supercapacitor has excellent tensile (three times the length without breaking), twisting and compression properties. Moreover, it exhibits a large areal capacitance of 356.5 mF cm(-2) at 1.0 mA cm(-2), high energy density of 31.7 mu Wh cm(-2) at power density of 800 mu W cm(-2), and maintains 80% of the initial capacitance after five cutting/self-healing cycles, as well as outstanding cycling stability. Meanwhile, the integrated PVA/PA-PANI (0.8 M) supercapacitor possesses high areal specific capacitance of 356.5 mF cm(-2) at 1.0 mA cm(-2) and still reach 167.5 mF cm(-2) at 5 mA cm(-2). The specific capacitance remains about 160% of the initial capacitance after 5000 cycles. The remarkable electrochemical properties are attributed to the high ion diffusivity and low charge transfer resistance benefiting from the integrated all-hydrogel-state prototype. The novel self-healing integrated flexible supercapacitor with excellent capacitance performance and mechanical properties is expected to broad prospects for energy storage equipment in wearable electronics. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Hydrogel electrolytes are crucial for the fabrication of flexible supercapacitors, with a self-healing integrated flexible supercapacitor showing excellent electrochemical properties and mechanical performance, offering promising prospects for energy storage in wearable electronics.